Interlocking shockproof electrical plug



B. F. NAUSLAR 2,643,364

INTERLOCKING SHOCKPROOF ELECTRICAL PLUG Filed April 2, 1949 June 23, 1953 INVEN TOR. BENJAMIN E NAUSLAI? AGENT Patented June 23, 1953 INTERLOCKING SHOCKPROOF ELECTRIC PLUG Benjamin F. Nauslar, San Diego, Calif.

Application April 2, 1949, Serial No. 85,075

1 Claim. 1

My invention relates to an interlocking shockproof electrical plug, and the objects of my invention are:

First, to provide a combined shockproof and interlocking electrical plug for conventional household use;

Second, to provide a plug having combined electrical contacts and plug locking actuator means;

Third, to provide interlocking male and female plugs which are interchangeably useful with conventional plugs now in use;

Fourth, to provide contacts and interlocking means which may be incorporated in conventional male and female electrical plugs with a minimum of changes therein;

Fifth, to provide a shockproof electrical plug of this class which is interlocking and in which the electrical contacts of the female plug portion are inaccessible to any instrument inserted directly through the male contact receiving openings of the female plug; and

Sixth, to provide an interlocking shockproof electrical plug of this class which is very simple and economical of construction, efficient in operation and which will not readily deteriorate or get out of order.

With these and other objects in view, as will appear hereinafter, my invention consists of certain novel features of construction, combination and arrangement of parts and portions, and a certain modification, as will be hereinafter described in detail and particularly set forth in the appended claim, reference being had to the accompanying drawings and to the characters of reference thereon, forming a part of this application, in which:

Fig. l is an end view of the female component of my interlocking electrical plug; Fig. 2 is a longitudinal sectional view thereof, taken from the line 22 of Fig. 1; Fig. 3 is a longitudinal sectional view taken from the line 3--3 of Fig. 1; Fig. 4 is a side elevational view of the male component of my interlocking electrical plug; Fig. 5 is a fragmentary sectional view taken from the line 5-5 of Fig. 4; Fig. 6 is a side elevational view of the structure shown in Fig. 4, taken 90 to that as shown in Fig. 4; Fig. 7 is an end view of a modified form of my interlocking shockproof electrical plug; and Fig. 8 is a longitudinal sectional view taken from the line 8--8 of Fig. 7.

Similar characters of reference refer to similar parts and portions throughout the several views of the drawing.

The male plug frame I, male plug contacts 2 and 3, female plug frame t, female plug contacts 5 and ii, and the insulation plates I and 8 constitute the principal parts and portions of my interlocking electrical plug.

The female plug frame 4, shown in Figs. 1, 2 and 3 of the drawing, is a substantially conventional female plug frame, produced and sold in large quantities. This female plug frame 4 is provided with a pair of male contact receiving openings la, adjacent to which are ledges ib, disposed at right angles to the axis of the open-= ings 4a and the axis of the plug frame 4. Sup ported within the female plug frame 4 are the female plug contacts 5 and 6. These contacts 5 and 6 are combined electrical contacts and male contact actuating springs, which tend to force the offset ledge portions 2a and 3a of the male plug contacts 2 and 3 into engagement with the ledge portions 42) internally of the female plug frame ihe male plug contacts 2 and 3 are rigidly secured to the male plug frame I, which is a conventional electrical plug frame, common to many electrical appliances now in use. It will be noted that the female plug contacts 5 and 6, as shown in Fig. 2 of the drawing, are connected to the socket end terminal l2 and the socket screw band I3 of the conventional electrical plug structure.

It will be noted that the insulation plates 7 and 3 are each wedged into the U-shaped portions 5a and Ga, respectively of the contacts 5 and 5, as shown in Fig. 2 of the drawings, for maintaining said contacts 5 and 6 in the recess portions 4c and id, respectively, of the female plug frame t. The contacts 2 and 3 in connection with the male plug frame 1 are provided with curved end portions and 3b, which are en-- gageable with the angularly inclined portions 513-: and 6b of the contacts 5 and 6, as shown in Figs- 2 and 3 of the drawing, and particularly disclosed in Fig. 3 of the drawing, wherein the male plug contact 2 is illustrated by dash lines engaging the female contact portion 6b at its curved end 2b.

The operation of my interlocking electrical plug, as shownin Figs. 1 to 6, inclusive, of the drawing, is substantially as follows:

When the male plug contacts 2 and 3 are inserted into the openings 4a in the female plug frame 4, the curved end portions 2b and 3b of the male plug contacts 2 and 3 engage the inclined portions 519- and 6b of the female plug contacts 5 and 6, which are resilient electrical conducting contacts, which tend to rotate the In order to remove the male plug contacts 2 and 3 from their engaged relation with the ledges 4b of the female plugframe. 4, themale. plug frame I is grasped at itshandle-portion'la'" and rotated in a clockwise direction, slightly deflecting the resilient female plug contacts -and;;-l5.:

6, whereby the ledge portions 2a and 3a ofthe male plug contacts 2 and 3 are disengaged-with the ledge portions 4b of the female plugmfr-amee 4, as shown in Figs. 2 and:.3 of the drawing, permitting axialwithdrawal 'of the male plug con-..

tacts'2 and 3 from the openingsfla' inithe female plug frame "4.

In" the modification, as'shownfint'Figs; '7"and.l 8 of the .drawing, ,the "partsi,are-designated as follows? The female plug frame 9, female plug icontacts I0, and thefmale contact operating ,spririgs ,I I The female plug frame 9 of the modified 'struc-..

ture, shown particularly inFigJJB of the-drawing... is similar to' the female plug frame 4 hereinbefore'. 3o

described; The: contacts. "I9"' of' the modified structure; shown in" Figi'18 of the :drawing,. ex=

tend'only to the innersurface of the ledges 9d of J the female plugfframe "9," which"correspond with" the ledge's' lb'of'thethereinbefore described structuredisclosedinFigsil to '3 of-the drawing. The. insulation "member'sl 4 secure 'the' contacts I D in;

positionin 'a"similar"manner. tothe 'securement 1 ofthe contacts'fi and'tjhereinbefore described.

in connection with the female plug frame 4. 4o

Opposed to each' of the .contacts I 0, only 1 one of which'-is disclosed in Fig. 8 Iofthe 'drawingis" a male 1 contact operating spring I I ,5 whichf'is' not an'electrical conductorrbut' which forces the. male plug contacts 2 and? intdengagement with'thefemale plug, contacts 10; it being notedthat the same male plug. used-in connection" with the" structuredi'sclosed'in"Figs; 1 11713 of the drawing; is operated in connection with .the structure shown-'in-Figs': 7"and "8 of the drawing."

The operation ofthe 'modified structure shown. in Fi'gSf 7 and-8 of-the drawings is substantially, asfo'llowsr When the -male-contacts '2 and 3 "'are' 'inserted into the openings-9b "in-the female plug frame.

9, the -"ledge portions 2a"and '3a are forced :into" engagement with-the contact portionsIO, resting ,i' orr-the inner ledges "9a of the female'plug'frame 5, which correspondto' the ledges 4210f -th'efe' male plug frame 4 hereinbeforedescribedin con- 0 nection'with Figsjl to"3 of thedrawing. When the male plug=is not engaged with the female! plug, 'as shown-"in Fig-'8 of'thedrawing,"an'd the openings to an the-fema1e plug-frame Qare" un obstructed, the insertion of a pin or. other sma11 5r instrument into the openings 9b fby'achild, or. other innocent person; would not 'cause'electricalf contact, due to' tha'obscure relationship ofth' contacts I ll behind 'the ledge'Qa, all as-shown in Fig.8 of:the drawing-:

Thus; the obscure relationship"of the contactsiil -rearwardly= of-the "ledge 9d provides fo'r" shock proof conditionaof the z plug :;-.disc1osed -in Fi'g; 8

of the drawing, in combination with the interlocking feature, wherein the ledges 2a and 3a of the contacts 2 and 3, disclosed in Figs. 5 and 6 of the drawing, engage the contacts I0, shown in Fig. 8 of the drawing, causing longitudinal or axial interlocking relationship of the male and female elements of the electrical plug, which is urged-and maintained bywthe-springs "II engagingzthe male-contacts 2 and '3, tending to rotate the male plug frame I in a counterclockwise direction.

Though I .have .shown and described a particular"construction; combination and arrangement of parts and portions, and a certain modi- -ficati'on,"I do-not-wish to be limited to this particular construction, combination and arrangement-,nor"to'the-modification, but desire to include inithe scope of my invention the construction, combination and arrangement, and the modification,- substantially as .set .forth in the appended claim.

Having thus described my 'invention,..what I' claim as new and desire to secure .by Letters Patent is:

Iri a shockproof interlocking electrical 'plug assembly a female-plug frameand 'a male .plug

frame having-a common axis, saidfemale plugframe having slot openings of similar character.

and similarly spaced on opposite sides of said axis, said 'femaleiplug frame having ledges at the ends of said slot openings saidfemale plug frame having an external screw-threaded conductor sleeve and a center terminal, l oppositely. disposed electrical contacts terminating on the inner surfaces of said ledges. and. individuallyconnected withsaidsleeve and said terminal, said male plug frame having. a pair-of .malecontacts spaced on opposite sides of said axis andextending through said slot openings, oppositely disposed springs I mounted 'w-ithinsaidfemaleplug frame-in opposing relation to said ledges andengaging said malecontacts so asto urgesaid male contacts alongwithflthe male 'plug-frame-to rotate in onewithnsaid one-direction, said portions-engaging said ledges and first tmentioned contacts when the male plug .is rotated by the springs through I a small .anglelof. rotation, the-first mentioned contacts being vdisposedton saidcledges at points slightlyremoved fromnalignment-with said slot "openings-in the direction. of said rotation, where by the plug is made shockproof as-well as interlocking-s BENJAMIN Fl NAUSLARH.

RferencesCitedin the file of this patent UNITED STATESIPATENTS Number Name a Date 1,376,068 Benjamin Apr. 26, 1921 1,618,939- Ma'rth Feb. 22,192? 1,890,484 A11enic Dec. 13," 1932 1,957,773 Good May 8, i934 1,966,'156 Witch'el" July lit-1934 2-,1 7 0,359. Wirth' Aug 22,1939 I FOREIGN PATENTS Number Country Date 852,953. France Mar. '7, 1940- 

